The present invention relates to aiming devices, and more particularly to optical scopes having a tool-less rezero system and/or a zero locking system.
The popularity of target shooting and other dynamic shooting sports has increased over the past several decades. The competitive nature of shooting and the desire to have well placed shots has led to the development and commercialization of a variety of aiming devices. A popular aiming device for short, medium and long range shooting is the optical scope.
Optical scopes are usually used on firearms, such as rifles, shotguns and handguns to aid the user in aiming at and precisely engaging a target when firing the firearm. A scope is typically mounted atop the firearm in a location above, and longitudinally aligned with, a barrel of the firearm. The scope, via its reticle, defines an aiming point coincident with the point of impact of a projectile, such as a bullet, on a target. The reticle can be in the form of a cross-hair, dot, post or other type of sight element. A number of optical lenses are also present in the scope tube to aid in viewing the target and in some cases magnifying the target.
Before using a firearm having an optical scope attached thereto, a careful user will sight in or “zero” the scope. That is, the user will adjust the vertical and horizontal position of the reticle, as viewed through the scope, to compensate for elevational and side-to-side misalignment of the scope with regard to the firearm barrel, distance to the target, ballistic characteristics of ammunition and other factors. This is accomplished by adjusting the elevation, or vertical position, and windage, or horizontal position, of the reticle.
Most optical scopes include windage and elevation adjustment knobs. These knobs are rotatably mounted to the scope tube and mechanically connected to the reticle. By rotating a knob, a user can move the reticle in a desired direction (typically up/down and left/right) to set the reticle in a predetermined configuration corresponding to a desired point of impact of a bullet shot from the firearm. Again, this process is called sighting in or zeroing the scope or firearm.
Some scopes are outfitted with adjustment knobs that remain rotatable in all conditions, that is, when the knob is being used to adjust the reticle, and even after the adjustment is fully completed. An issue with such always-adjustable knobs is that if the knob is inadvertently bumped in the field or transit, the reticle will also move, causing a misalignment thereof with a desired point of impact. In other words, the scope will no longer be properly zeroed or sighted in. To address this issue, some scope manufacturers offer the scope with scope knob caps that cover the knobs so they cannot be inadvertently rotated. These covers, however can be inadvertently lost, and take time to install and remove.
Other scope manufacturers include a threaded locking ring that physically locks the knob in a fixed rotational position after adjustments have been made to set the reticle. A well-known and popular scope with such zero locking capability is the Accushot® UTG 3×12×44 mm Scope, available from Leapers, Inc. of Livonia, Mich. This type of locking ring is disclosed in U.S. Published Patent Application 2017/0199009 to Ding, which is hereby incorporated by reference in its entirety. While this type of zero lock is durable and easy to use, it still can require the use of tools in some applications.
Some scopes can include a removable zero cap. This cap can include the number zero and subsequent numbers and bars, equally spaced from one another. The zero and its bar typically are aligned with a reference bar on the base of the knob fixed to the scope to indicate to the user that the adjustment knob has not been moved relative to a sight in the scope. The removable zero cap can be attached to the remainder of the knob with a screw. After a user sights in the scope, many times, the zero bar is not aligned with the reference bar on the base because the knob and cap were rotated to sight in the scope. Thus, to “rezero” the knob, the user can remove the screw with a tool, remove the cap, then rotate the cap and set it back on the remainder of the knob with the zero bar aligned again with the reference bar. The user can then tighten the screw with a tool to secure the zero cap in this orientation, thereby rezeroing the adjustment knob. While this type of removable zero cap is easy to use, it requires the use of tools and can be prone to being dropped, lost or contaminated with dust and debris, which can impair operation of the adjustment knob.
Accordingly, there remains room for improvement in scopes, and in particular, the zeroing and locking features of adjustment knobs used in conjunction with scopes.